Rheostat



Sept. 24, 1940. J Q STEARNS 2,216,054

RHEOSTAT Filed May ll, 1937 Jealen Patented Sept. 24, 1940 PATENT OFFICERHEosTAT Jason C. Stearns, Worcester, Mass. Application May 11, 1937,serial No. 141,964A

3 Claims.

This invention relates to that class of electric rheostat or the likedevice in which a translucent knob, having a light behind it, can beemployed, While in one vposition to connect the battery with a carheater r the like and, when in that position, can be turned to changethe amount of current going to the heater and, when in another positionlongitudinally can, without disconnecting the heater, also connect thebattery ywith an electrically operated device, such as a fog light, forexample.

The principal objects of the invention are to provide simple andinexpensive means inside ythe device by.,wh-ich the knob can be made toboth turn andreciprocate a shaft for the purpose of connecting anddisconnecting the circuits; to provide a lamp socket, adapted itself tobe ymoved longitudinally and turned, with means for transmitting thismotion to a shaft which-controls the connection of the battery withelectrical devices, and to provide this socket inside the device whereit is out of the way of dust, rain and the like and therefore isprotected from all ordinary` accidents.

Other objects and advantages of the invention will appear hereinafter.

Reference is to be had to the accompanying drawing, in which Fig. 1 is aside elevation `of a device constructed in accordance with thisinvention;

Fig. `2 is an end view as indicated by the arrow 2 in Fig. 1;

Fig. 3 is a diametrical, longitudinal sectional view of the entiredevice on enlarged scale;

Fig. 4 is an elevation of a part of it as indi- Uca-ted 'by the arrow 4in Fig. 3;

Fig. 5 is a sectional view on the line 5-5 of Fig. 3;

Fig. 6 is a view with parts omitted corresponding with Fig. 3 exceptthat the operating knob is pulled out instead of being pushed in;

Fig. '7 is an elevation of the carrier plate, and

Fig. 8 is an elevation of the bre washer rthrough which the motion ofthe knob is transmitted to the line making and breaking shaft.

Many of the parts shown in the drawing are old and well known 'but theywill be described in connection with the features of the inventionitself.

'I'he device is shown as mounted on a bracket I0 which, of course, isxed in a definite position. This bracket has a plane end which is xed ona hollow nut ll by means of two nuts l2 and I3 screwed up on the nut IItoward each other to grip the end of the bracket. These parts,

therefore, are stationary. Inside the nut l! is a lamp socket i5 in theform of a hollow tube of metal provided with an lopen slot I6 extendingfrom one end to the other and an opposite longitudinal groove iii. Onone end of this socket there is an enlargement Il and inside is ashoulder i8 sothat the inside of the socket is of two differentdiameters.v -In this socket the base I9 of the lamp is placed. This basehas the usual radial pins 2i) for being received in the slot I5 andgroove I4 and it also has a terminal projection 2l for engagement with aspring pressed conducting plunger..

The nut i l abuts against the outside of the shoulder i8 which, in thenormal position of the lamp, holds the position of that shoulder. Thelamp is located in a hollow space in the interior of a translucentoperating rnemberor knob 22 which is provided with such a shape outsidethat it can be used for turning the parts as well asy for moving themlongitudinally. This knob extends with a ririctional fit into a recessin a translucent face plate E3r which is mounted on the threads oi thenut il, held from rotation by ,engagement with the bracket lil. `Itcovers the plate having a cylindrical ange 26 at one4 i end. Beingmounted on the nut il this plate 25 is stationary. It will be seen thatthe cylinder l5, which carries the lamp ysocket I9, extends through thenut Il and through the plate 25.

Inside the flange `26 is located a swingingly oscillatable dishedcarrier plate 21. It has a crossshaped opening 28 therethrough with apair of integral guides 29 projecting from its face longitudinally.Thisplate is made from metal and aside from the rfeatures so far.described is provided with` a pair of stops 30 on the circumference onthe other side` for engagement with a stop pin 56 on the stationary disc25. A pair of radial slots 3i and 32 extend through it.

Inside the carrier plate is an insulating disc 33 which is iixed on ahub 34 carried by the operating shaft 35. This disc is provided withperiorations therethrough for receiving headed over projections 36 onthe end of the cylinder I5 for fastening the two parts together. Thedisc 33 also is provided in its outer circumference with two oppositeslots 31 for receiving the guides 29. In this way it will be seen thatthe hollow cylinder I5 is fixed, as far as turning is concerned, withrespect to the carrier plate 2| but that it is adapted to slidelongitudinally with respect to the other along these guides 29.

On the outside of the carrier plate is located a loose insulating disc38 against which bears the end of a coil spring 39 located on the shaft.The other end of this spring bears on an arm 40. This arm is providedwith a non-circular perforation to cause it to turn with thenon-circular shaft 35 on which it is slidingly mounted. Beyond this armand xed to the shaft is an insulating or bre collar 4| and a metallicconducting collar 42, both held in position by a nut 44 which is locatedon the screw-threaded end of this shaft and serves to tighten up thecollars 4| and 42.

At the end of the device is an insulating disc 45 which is held in placeby longitudinal arms 43 on the metal disc 25. This disc 45 is providedwith three terminals, a battery terminal 46, a heater terminal 4'| and aterminal 48 for a fog light or other electrical instrument. The batteryterminal is provided with a contact 49 extending down into the center ofthis hollow disc 45 and also with a rivet 55, which also constitutes aconnecting member to a plate 5|. This plate 5| is connected with anarcuate resistance coil 52 which extends around part of thecircumference of the disc 1n a recess 53 placed therein for thatpurpose. The plate 5| is small and is located at one end of the spring,of course, and the arm 4U is capable of being turned around in contactwith this resistance to connect the heater with the battery and vary theresistance and therefore the temperature and the amount of currentconsumed.

The arm 40, when located on the plate 5|, gives full force to the heaterand when moved beyond it engages the non-conducting surface of the discso that the heater is disconnected. This action takes place in eitherposition of the knob 22, that is, whether it is pushed in as shown inFig. 3, or pulled out, as shown in Fig. 6. The arm rests at its rear endall the time on a metallic conducting circle 54, connected to the heaterterminal 4l.

When the knob is pushed in, as shown in Fig. 3, the terminal 49 and aterminal 55, from the fog light or other electrical instrument, rest onthe fibre or insulating collar 4| and the current is not conducted tothis instrument. When the knob 22 is pulled out, as shown in Fig. 6,these two terminals 49 and 55 engage the metal collar 42 and the currentis conducted from the battery to the fog light or the like. This, inspite of the fact that the current is also conducted to the heater orsuch other instrument as may be substituted for it. Turning the knob 22does not affect this connection.

The turning of the knob results, of course, in the turning of the arm 40and the rectilinear reciprocation of the knob results in the connectionor disconnection of the battery with the fog light or other instrument.The heater is connected up all the time unless the arm 40 is turnedbeyond the plate 5|.

The flat flanges of the discs 25 and 2`| bear on each other. There is aslight beveled edge protuberance 51 on the contacting surface of thedisc 25 which snaps into and out of the slots 3| and 32 in the carrierplate to show, by the feeling or by producing a clicking sound, when thecurrent is turned on or off the heater as the protuberance enters orleaves the slots.

It will be seen, therefore, that by the use of the hollow cylinder |5and its connection with the insulating disc 33 the construction of sucha device is simplied, its cost reduced, and its protection from theelements assured.

Having thus described my invention and the advantages thereof, I do notwish to be limited to the details herein disclosed, otherwise than asset forth in the claims, but what I claim is:

1. In an electric device, the combination of a supporting bracket, anut, means for fixing the nut in stationary position on the bracket, adisc fixed with respect to the nut, a rotatably oscillatable carrierplate located in contact with said disc, a hollow lamp socket movablymounted within the nut, an insulating disc fixed to the lamp socket, ashaft to which said insulating disc is fixed, means carried by saidshaft for conducting a current from a source of power to one of twoelectric appliances in accordance with the longitudinal position of theshaft, and means carried by the shaft for varying the current to the oneof them which is in circuit when the shaft is in either one of itslongitudinal positions.

2. In an electric device, the combination of a nut, means for fixing thenut in stationary position, a dished disc fixed with respect to the nut,a dished carrier plate located mostly within and in contact with saiddisc, said carrier plate having longitudinal guides, a hollow lampsocket movably mounted within the nut, an insulating disc iixed to thelamp socket, a shaft to which said insulating disc is fixed, means onsaid disc for guiding it longitudinally by means of said guide, meansfor moving the lamp socket longitudinally and for rotating it, meanscarried by said shaft for conducting a current from a source of power toone of two electric appliances in accordance with the longitudinalposition of the shaft, and means carried by the carrier plate forvarying the current to one of them.

3. As an article of manufacture, an electric device having a batteryterminal and two other terminals, a shaft having an insulating ring anda metallic ring xed thereon for connecting or disconnecting the batteryterminal with respect to one of the other terminals, a hand knob movablelongitudinally, a metallic lamp socket within and supporting the knoband projecting there- Vfrom in the device, comprising a conductingsleeve, said lamp socket being in the electrical circuit at all times,an insulating disc movable with the sleeve, a metallic carrier plateconnected with the insulating disc to turn therewith but not to movelongitudinally therewith and having guides for the insulating disc, anda metal plate in fixed position and in contact with the carrier plateand otherwise spaced therefrom to furnish a protected space for saidguides.

JASON C. STEARNS.

